From 4cd5efd37913fc2386a031f63e65876ab0b298e5 Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Thu, 23 Feb 2023 15:53:47 +0000
Subject: [PATCH] cmake: Check compiler features

---
 cmake/bitcoin-config.h.in |  9 +++++++++
 cmake/introspection.cmake | 23 +++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/cmake/bitcoin-config.h.in b/cmake/bitcoin-config.h.in
index 759bcb8d1cb28..7a3cf24f440a5 100644
--- a/cmake/bitcoin-config.h.in
+++ b/cmake/bitcoin-config.h.in
@@ -6,6 +6,9 @@
 
 #define BITCOIN_CONFIG_H
 
+/* Define this symbol if type char equals int8_t */
+#cmakedefine CHAR_EQUALS_INT8 1
+
 /* Version Build */
 #define CLIENT_VERSION_BUILD @PROJECT_VERSION_PATCH@
 
@@ -119,6 +122,12 @@
    */
 #cmakedefine01 HAVE_DECL_SETSID
 
+/* Define if the visibility attribute is supported. */
+#cmakedefine HAVE_DEFAULT_VISIBILITY_ATTRIBUTE 1
+
+/* Define if the dllexport attribute is supported. */
+#cmakedefine HAVE_DLLEXPORT_ATTRIBUTE 1
+
 /* Define to 1 if you have the <endian.h> header file. */
 #cmakedefine HAVE_ENDIAN_H 1
 
diff --git a/cmake/introspection.cmake b/cmake/introspection.cmake
index 624f70ad10cb9..3e637bc4d04e8 100644
--- a/cmake/introspection.cmake
+++ b/cmake/introspection.cmake
@@ -240,3 +240,26 @@ check_cxx_source_compiles("
   }
   " HAVE_SYSCTL_ARND
 )
+
+check_cxx_source_compiles("
+  #include <cstdint>
+  #include <type_traits>
+
+  int main()
+  {
+    static_assert(std::is_same<int8_t, char>::value);
+  }
+  " CHAR_EQUALS_INT8
+)
+
+check_cxx_source_compiles("
+  int foo(void) __attribute__((visibility(\"default\")));
+  int main(){}
+  " HAVE_DEFAULT_VISIBILITY_ATTRIBUTE
+)
+
+check_cxx_source_compiles("
+  __declspec(dllexport) int foo(void);
+  int main(){}
+  " HAVE_DLLEXPORT_ATTRIBUTE
+)